K2: “This isn’t Jerry Garcia’s marijuana”

February 20, 2010, 3:28 pm

An article in the Columbia Missourian this week reported on a move in the Missouri House of Representatives to ban one of the ingredients in the synthetic cannabinoid K2.

K2 has an interesting history. In the 1990s, scientists at Clemson University synthesized a number of cannabinoid analogues as part of their research into cannabinoid receptors. They found that there were two major receptors: CB(1) — located mainly in the central nervous system; and CB(2) — located in T cells, macrophages, and other components of the immune system. The psychoactive effects of cannabinoids are mediated almost entirely by the CB(1) receptors. Possibly following processes outlined in papers that came out the Clemson lab, street “chemists” manufactured some of the psychoactive analogues and marketed herbal mixtures of tobacco laced with the product under names such as “K2” and “Spice”.

As of now, these synthetic cannabinoids are not illegal (although they have been banned by the military). Almost nothing is known about the clinical effects of these chemicals — the few scientific articles that exist deal mostly with laboratory analysis and physiology at the cellular level. In fact, it is not clear to me whether K2 represents a serious problem or media hyperbole. For whatever reason, the Missouri state legislature has focused on banning one of the ingredients found in K2 (most likely the research chemical JWH-018). MSNBC quoted one state Representative, Jeff Roorda, as remarking that “This isn’t Jerry Garcia’s marijuana”.

The problem with such a political solution is that products such as K2 are moving targets. When the German Health Authorities prohibited JWH-018 in 2009, analysis of samples acquired after the ban detected not JWH-018 but another analogue JWH-073. It is possible that chemicals substituted for those made illegal might be more dangerous than the banned substance. In addition, if the composition of products such as K2 change constantly it may be difficult to know what to expect clinically, or the optimal management of patients who report exposure to these mixtures.